As illustrated by U.S. Pat. Nos. 2,429,314 to Goldman, 4,177,304 to Berry and 4,949,667 to Yoshida et al, coating a web by passing it through a nip between opposing rolls and supplied with a bath or puddle of coating material, is known. The rolls may have ordinary smooth surfaces or may have surfaces with recesses. As shown in Berry, a roll may rotate freely and be movable for positioning into nip engagement.
Also known, as exemplified by U.S. Pat. No. 3,117,888 to Fox and German Auslegeshrift No. 1,037,337 of Fiberbond Laboratories, Inc., are filament coating processes. In the Fox process, coating liquid is applied as a plurality of filaments are converged into a single strand by a gathering device. In the Fiberbond process, untwisted yarn of parallel fibers adhesively bonded together is prepared by drawing of the fiber, soaking the fiber with adhesive at a dipping station formed by a nip between opposing rolls including a napped roll, and then collecting the fiber by opposing friction and pressure applied by a movable cork-covered roll against the napped roll. In a modification, a movable pressure roll presses fiber against an adhesive-bearing, dip or transfer roll, and thereafter the fiber is collected; and pressure is regulated through a lever and weights.
Despite the foregoing and other improvements, there is a need for an improved filament coating process, and in particular a filament coating process that has beneficial application in making pultruded rod.